It happened to me... I developed allergies when I was an adult

If you were going to suffer from asthma or eczema you might assume these conditions would develop as a child.

However, adults who have never had allergies can suddenly develop asthma, eczema or food allergies.

'Although most people develop allergies when they are children, a small number can find themselves sensitised, or reacting to allergens like pollen, foods or house dust mites when their immune systems have already fully matured,' explains Dr Adrian Morris, an allergy specialist at the Surrey Allergy Clinic.

UK population studies of adult-onset asthma suggest that there are around 4.6 women in 1000 who develop the respiratory condition in adulthood and 3.6 males in every 1000.

The trend towards adult-onset asthma increases with age, so older people are more likely to develop the condition.

Flu and depression

Common triggers of allergy development in adulthood include flu, colds or other viral infections, depression, anxiety or regular exposure to irritants such as cigarette smoke, perfumes and chemical fumes and some medicines.

According to studies, such as that carried out by researchers at King’s College London and published in the journal Thorax in 2000, paracetamol may be linked to the development of asthma in adulthood and can make existing asthma worse.

'Drugs known as proton-pump inhibitors, including omeprazole, and lansoprazole, are used to relieve acid reflux by neutralising acid in the stomach and reducing its ability to break down proteins in food,' explains Dr Morris.

'These undigested proteins then pass through into the gut where they can cause allergic reactions in some people.'

Pregnancy and menopause

Hormonal disruption is another common risk factor for late allergy onset.

Women going through the menopause are more likely to develop adult-onset asthma.

Pregnancy can also leave a woman with a lifelong sensitivity to certain allergens.

'Pregnancy itself seems to be a catalyst for switching the response of the immune system,' says Dr Morris.

'We don't understand exactly what the mechanism is, but what we see is that allergic diseases such as asthma, rhinitis and skin allergies may become more problematic and difficult to treat during and after pregnancy.

'Occasionally it can go the other way and allergies seem to improve after a pregnancy.

'It has to do with the "temporary immune tolerance" induced in pregnancy as the baby is seen as a "foreign object" and so the mother's immune system would normally have a problem with this foreign protein source in the body of the mother.'

'It happened to me'

Melanie Knibb, 35, a secondary school teacher in Watford, Hertfordshire, had never experienced any type of allergy until she became pregnant with her second child in 2010.

'My first pregnancy was a joyful experience. Really easy and no problems,' she says.

Her eldest child, John-Paul, who is now six, was born naturally and Melanie was a delighted new mum.

But when she fell pregnant with her second child, Amélie, it was a completely different story.

'In the third trimester, I started to suffer from a streaming nose, blocked sinuses and itchy skin all over.'

'I couldn't believe it. I grew up in the countryside surrounded by fields and I'd never had hayfever before.

'None of my family have allergies either.'

When Amélie was born, the symptoms stopped.

Medication

However, in February 2012, when Melanie fell pregnant for the third time, the hayfever came back with a vengeance and this time, it lasted throughout the entire pregnancy.

She was advised to take antihistamines and three courses of antibiotics to relieve the symptoms of sinusitis.

When her third child, Eleanorè, was born, Melanie's allergies didn't go away.

'My symptoms were as bad as ever and worse still, Eleanorè was born with eczema.'

Eleanorè was also intolerant to multiple types of food. At six months old, after eating a tiny piece of bread, she had a severe reaction that caused swelling and a rash all over her body.

Eleanorè was treated with prednisolone and is still now allergic to all tree nuts, soya, seeds and dairy products.

For her fourth pregnancy, Melanie declined all hayfever medication to help with her own symptoms, believing that they had caused some of the problems suffered by Eleanorè.

'It was a terrible time and my symptoms were severe, but I was determined to stay drug free.'

Elise, now nine months old, was born without allergies.

Melanie is still breastfeeding, but when she stops she will go back to her daily routine of taking antihistamines to reduce the severity of her symptoms.

Then she is hoping to get a course of desensitisation therapy (see below) to turn back the clock and dampen down her body's heightened immune response to pollen.

'I'm going to get rid of this. I will find a way,' she says resolutely.

Remedies

Antihistamines are readily available and can be bought over the counter without a prescription.

'There are a number of different types of antihistamines; some have been used for many years, some are improvements on old drugs, and new antihistamines are being developed all the time,' says Dr Morris.

People suffering from eczema can use emollient lotions and creams to moisturise their dry skin.

'Some emollients may also contain slight amounts of antibacterial chemicals to reduce the risk of infection or steroids, which can reduce inflammation.'

Immunotherapy, often referred to as desensitisation, can help reduce the symptoms of allergies, particularly those caused by insect bites or allergic rhinitis, and in some cases, prevent them altogether.

'Patients are given gradually increasing doses of allergen extracts over a period of time, even years and this can result in them developing a tolerance.'

Recent research suggests that one in ten people in the UK uses some form of alternative or complementary remedy for general health and wellbeing.

According to Dr Morris: 'This may be an option for some, but is a matter of personal choice. Some people with an allergic illness will have used or considered alternative treatments, but evidence for whether or not they work is purely anecdotal.'

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